#include <iostream>
using namespace std;

class c1
{
	public:
	class c2
	{
		public:
			static void set(c1& obj,  int val) { obj.a = val; }
	};
	
	private:
		int a;
};

int main () {
  c1 o;
  c1::c2::set (o, 123);
}